Question

Refer to Exercise 2.65 (p. 59) and the Teaching of Psychology (May 1998) study in which students assisted in the training of zoo animals. A sample of 15 psychology students rated “The Training Game” as a “great” method of understanding the animal’s perspective during training on a 7-1 point scale (where 1 = strongly disagree and 7 = strongly agree).The mean response was 5.87, with a standard deviation of 1.51.
a. Construct a 95% confidence interval for the true mean response of the students.
b. Suppose you want to reduce the width of the 95% confidence interval to half the size obtained in part a. How many students are required in the sample in order to obtain the desired confidence interval width?